CO2 Timing Chart

Carbon Dioxide Flow Chart for Emitter Systems
(to estimate total minutes of operation)
1000 ppm (B) Flow in Cu.Ft./Hr
--- 5 10 15 20
(A) Cu.Ft. of Area (C) Time in minutes
400 4.8 2.4 1.6 1.2
600 7.2 3.6 2.4 1.8
800 9.6 4.8 3.2 2.4
1000 12.0 6.0 4.0 3.0
1200 14.4 7.2 4.8 3.6
TABLE KEY
(A): Total cubic feet of the enclosure (L x W x H)
(B): Rate of flow shown on the 'flow rate tube'
(C): How long it takes to inject CO2 into the grow space shown in minutes.
Carbon Dioxide Tank Cycles
(used to determine tank life)
CO2 Flow Rate
Cu.Ft./Hr
Minutes of Operation
1 2 4 6 8 10 12
10 52.45 26.22 13.11 8.74 6.56 5.24 4.37
15 34.96 17.48 8.74 5.83 4.37 3.50 2.91
20 26.22 13.11 6.56 4.37 3.28 2.62 2.19
25 20.98 10.48 5.24 3.50 2.62 2.10 1.75
30 17.48 8.74 4.37 2.91 2.19 1.75 1.45
Select the CO2... flow rate and minutes of operation that will give you the proper ppm of CO2 for your growing area. Next, find the values that correspond to these two settings in the Carbon Dioxide Tank Cycles Chart and multiply that number by your tank size.

Example: From the Carbon Dioxide Flow Chart for Emitter Systems you determine that you need 15 Cu.Ft./Hr of CO2 at 6 minutes of "On" time. From the chart above, the cross reference settings is 5.83. To determine the maximum number of cycles your tank will accommodate, multiply you tank weight* by 5.83. If you had a 20lb tank, the total number of cycles possible from a full tank would be 117 (20 x 5.83).

* Tank weight refers to the actual weight of liquid CO2 int he cylinder and not the weight of the empty tank. A standard 20 lb. tank therefore, has 20 lbs. of liquid CO2 in the cylinder. Some standard tank sizes are 10, 20, 35 and 50 pounds. Even if you do not have a standard size tank, this method will work to determine the maximum number of cycles possible.